Denver Broncos quarterback Peyton Manning (18) throws the ball during the first half against the Washington Redskins at Sports Authority Field at Mile High. / Chris Humphreys, USA TODAY Sports

by Tom Pelissero, USA TODAY Sports

by Tom Pelissero, USA TODAY Sports

Here's one way to make sure the fan base stays engaged throughout the NFL season: Reach the midpoint with almost half the league separated by one game in the loss column.

Granted, only one of those 15 teams - the Dallas Cowboys, who lead the ugly NFC East at 4-4 - would make the playoff field if the season ended today.

But there's hope for teams that weren't supposed to have any, such as the New York Jets, Tennessee Titans, Oakland Raiders and Arizona Cardinals.

They're all within striking distance of the No. 6 seeds, which currently belong to two teams that went 11-21 combined in 2012.

The 4-3 San Diego Chargers would be in right now. So would the 5-3 Detroit Lions.

It's easy to forget the New Orleans Saints weren't a playoff team last season either, now that they're atop the NFC South at 6-1.

The same goes for the Kansas City Chiefs, who have gone from 2-14 to 8-0 - a game up on the Denver Broncos in the tough AFC West.

The rest of the division leaders are familiar with the postseason: New England Patriots, Cincinnati Bengals, Indianapolis Colts, Green Bay Packers and Seattle Seahawks.

But every time an Oakland or Arizona at least keeps things interesting as November approaches, it's a reminder that strange things can happen in the NFL.

Unless you're the Jacksonville Jaguars.

Here are key 10 questions that will be answered in the second half of the season.

1. Can Peyton keep it up?

Peyton Manning has put up some of the best numbers of his career - 71.2% completion rate, 29 touchdowns, 119.4 passer rating - in the Denver Broncos' 7-1 start. But his arm isn't what it used to be, which could become a greater factor as the weather turns, and his 37-year-old body has taken a beating the past few weeks. The Broncos haven't run the ball particularly effectively. Their defense isn't the same even with Von Miller back. The AFC front-runners live and die with Manning, putting a lot on his shoulders down the stretch.

2. Will another title contender emerge in the AFC?

The Kansas City Chiefs are the league's lone unbeaten, but the jury is out on whether their defense-first formula can carry them in January. The Indianapolis Colts sent a message in beating the Broncos two weeks ago, but they just lost top receiver Reggie Wayne. The New England Patriots have Bill Belichick and Tom Brady, which always will make them dangerous, but they've been slammed as hard as any team by injuries. The Cincinnati Bengals are coming on, but they haven't won a playoff game since 1990. Denver remains the team to beat. For now.

3. Who will emerge in the wild-card races?

If the season ended today, the San Diego Chargers would get the other AFC wild-card spot and the Detroit Lions would make the NFC field, along with the Seattle Seahawks, New Orleans Saints, Green Bay Packers, Dallas Cowboys and San Francisco 49ers. But eight teams (five in the AFC, three in the NFC) trail by a game or less - a list that includes the New York Jets, Oakland Raiders, Tennessee Titans and Arizona Cardinals. If no one makes a run to seize those final spots, 9-7 could be enough to earn multiple wild cards for the first time since 2009.

4. Who's the cream of the NFC crop?

Seattle's 29-3 blowout of the 49ers in Week 2 feels like an eternity ago. But the Seahawks are the top contender until proved otherwise - especially with the injuries they've faced on both sides of the ball and the fact that dynamic receiver Percy Harvin has yet to make his debut. A short-handed offensive line nearly gave away Monday's game at the St. Louis Rams. San Francisco has issues, too, but has won five consecutive games by an average of 22.6 points. And it's impossible to count out the Saints or Packers, who have the best quarterbacks of the bunch.

5. Can QB changes save embattled coaches?

The Minnesota Vikings still are trying to figure out who their quarterback is. So are the Houston Texans, whose decision to go with Case Keenum over Matt Schaub says a lot about how far Schaub has fallen - and perhaps what coach Gary Kubiak thinks he must do to save his job. Vikings coach Leslie Frazier figures to go back to Josh Freeman this week as a last-ditch effort to show his staff can work with a potential quarterback of the future, too. It's probably too late for Frazier, but Keenum showed in his starting debut he might be the spark the Texans need to rally.

6. What other coaches could be out of jobs?

Like Frazier and Kubiak, the Atlanta Falcons' Mike Smith and the Washington Redskins' Mike Shanahan made the playoffs last season and have contracts believed to expire after next season. Neither ranks high on any hot-seat list, though. Greg Schiano likely is in his final months, if not weeks or days, with the Tampa Bay Buccaneers. The New York Jets' Rex Ryan and the Carolina Panthers' Ron Rivera, among others, can't feel safe yet. And even the likes of Miami Dolphins coach Joe Philbin could be in trouble if their seasons head south.

7. Who's No. 1?

Jacksonville Jaguars coach Gus Bradley should be safe because, well, his boss knows he's not exactly working with much. (His predecessor, Mike Mularkey, probably thought the same thing but didn't have a new general manager on his side.) The Jaguars have been outscored 264-86 in their 0-8 start - an average defeat of more than 22 points. They aren't guaranteed the No.1 pick yet, though. The Bucs are winless, and the Vikings' brutal upcoming schedule could keep them in the mix if the Jaguars somehow (perhaps accidentally) win a game.

8. Which rookies will lift contenders?

If 2012 was the year of the rookie quarterback, with Andrew Luck, Robert Griffin III and Russell Wilson leading their teams to the postseason, this could be the year of the rookie running back - even though none went in the draft's first round. Giovani Bernard and Eddie Lacy have surpassed 500 yards from scrimmage for the Bengals and Packers, respectively. So has Andre Ellington, whose 154-yard rushing performance Sunday gave the Cardinals life. Montee Ball is getting his chance with the Broncos. And Christine Michael still might play for the Seahawks, too.

9. Late boosts?

Harvin, who had hip surgery in August, isn't the only player who could return from injury and make an impact - particularly in the NFC playoff chase. Receiver Michael Crabtree (Achilles) and pass rusher Aldon Smith (drug rehab) top the 49ers' list. The Packers should get back receiver Randall Cobb (leg) and pass rusher Clay Matthews (thumb). The Saints get some depth with linebacker Jonathan Vilma (knee). Bears quarterback Jay Cutler (groin) and linebacker Lance Briggs (shoulder) will be back sooner rather than later, too, though perhaps not in time.

10. Road to Super Bowl

Playing Super Bowl XLVIII at Met Life Stadium in East Rutherford, N.J., could present a unique challenge for the pass-happy NFL's main event: bad weather. That only heightens the focus on which teams can navigate the elements as the season rolls into the playoffs. If the postseason began today, four teams that play in domed or retractable-roof stadiums - Colts, Cowboys, Lions and Saints - would be in the field. They're 7-6 combined in outdoor games this season, but they (like everyone else) have yet to see subzero temperatures or snow.